Conventionally, a surface treatment is performed on optical elements using a transparent base material such as glass or plastic to reduce surface reflection of light. As such a surface treatment, a method exists for manufacturing a fine concave/convex pattern (for example, a moth eye pattern) on an optical element surface (for example, refer to PLT 1 and 2).
In these techniques, a master having a desired pattern formed on the surface thereof is used and transferring the pattern of the master to a sheet coated with, for example, a photosensitive resin or a thermosetting resin, enables inexpensive and mass production.
Furthermore, there is a method of forming a desired pattern on a cylindrical shaped quartz base using mastering techniques for optical discs. In this case, thermal lithography using thermal changes in an inorganic resist (for example, metal oxides made from one or more transition metals such as tungsten and molybdenum, among others) can be used. By using thermal lithography, thermal reaction is caused in only a central portion of the beam width which enables machining of a fine pattern exceeding the resolution limit of the laser light.
However, in exposure using mastering techniques for optical discs, variances in surface properties (waviness and unevenness) and shape (roundness) lead to adverse changes in exposure beam conditions. Furthermore, in the case of using thermal lithography, interaction between strain in the quartz base material and heating of the inorganic resist degrades pattern precision.